ford dealership- normal service? screw job? or normal screw job?

We will probably see power distribution modules at the front, middle and back of our vehicles with optical fibers transmitting the information to the modules. This will result in less wiring and easier manufacturing. Some of this may already be in use, but 42V will make it all work a lot better.

Module networking is already a fact of life. The Windstar (... now Freestar) is a shining example, having more modules than you can shake a stick at. Even the beloved Mustang..... The wiring diagram manual shows an ABS module, Restraints Control Module, Generic Electronic Module, Powertrain Control Module and Hybrid Electronic Cluster module. Let's not forget that this is one of the "simple" ones. These modules communicate over three different networks in various combinations..... Cadillac tried fibre optics in the Allante and they were a dismal failure.... the cable couldn't take the constant flexing as the doors opened and closed coupled with temperature extremes - I imagine that future endeavours will work better...

Important to remember that automobiles aren't very long.... high current circuits experience higher line loss than low current circuits but, in the grand scheme of things, it is rare to see much sacrificed to line loss in an automotive circuit. 14 volt systems are coming with alternators rated at well over 100 amps... these levels of current flow can tax the best laid out systems.

Jim Warman snipped-for-privacy@telusplanet.net

Sure, forgive me if I offended you. Voltage loss isn't what I normally think about, since it doesn't directly represent the actual loss of power. Just a different perspective I suppose.

Dana

I don't think it's a human nature issue, really. Mobile entertainment electronics were effectively a non-issue in the 1950s, even most of the

1960s. However, now we have a huge legacy of 12V entertainment and communications devices. As long as these devices are provided 12V service, I don't think 42V will present a major issue. In other words, radio interconnects and cigarette lighter sockets would need to still have 12V, and if this is the case, I suspect few would care.

There will also be a big market in 42V to 12V high-efficiency power converter bricks.

Dana

The problem that needs to be addressed as the voltages go up is circuit protection that detects arcing. A little 12V spark doesn't usually burn too far around it but you start getting a decent arc going it can light up a lot of flammable materials that are under dashes and seats etc. StuK

Do you think 42V presents a significantly greater risk of arcing?

Dana

that

start

Well somewhat. This might not be that big of a problem in some environments but the longer the arc lives the more chance of a fire starting. Bear in mind circuit protection now is based on burning of a fuse due to high current flow ( usually "infinite" due to a short). If an arc can exist longer before the current can increase enough to burn that fuse then there will be problems sooner or later. It is actually one of the hurdles that is stopping

42 volts from being implemented sooner. These systems exist on aviation systems but obviously don't need to be quite as robust on ground bound vehicles but some consideration must be made what with our litigation crazy society. A carbeque isn't as dramatic as a plane crash but there are a lot more people in cars day to day than in planes. StuK >

Both my 2004 F-150 4x4 and 1994 Corvette have alternators that put out a lot more than 100 amps. I believe the Corvette alternator puts out 140 amps. The F-150 is rated at 130 amps.

F SuperDuty and "big" Econolines are available with dual alternators for the ambulance package - the second alternator takes a preset amount of time before it comes "on line" to prevent glow plug damage. I have several ambualnces that I work on... still impressive to see 140 amp charging at idle....

Jim Warman snipped-for-privacy@telusplanet.net

Let's think about that for a moment. 14V * 140A = 1960W. Assuming the alternator is, say, 60% efficient, that's over 3200W load on the engine, or about 4.5hp. At idle ;-)

Dana